Tvfool Attached

I am having trouble with Channel 34 (33.1) I have a 4228HD antenna about 5' above my roof, I just recently started having trouble with this channel. I have the antenna joined to another antenna via a channel 34 Jointenna. The signal reads about 80% and then will drop to 40% and back to 80%. I was wondering what would be the most likely cause for this issue. The signal should be very strong in my area but it is somewhat distant. I am in the suburbs and there are many trees. Also, would tilting my antenna up help?

The link doesn't work. Try saving the chart on your computer (it's a PNG file), and attaching it to a post. Use the "Manage Attachments" button in the "Additional Options" section of the message-composition page.

Pending further information, my first guess is that your signal was improved by tropospheric enhancement which is common in many areas of the US from about late spring into the fall because of increased water vapor in the air. In late fall, winter and early spring the air tends to be drier, which reduces tropospheric enhancement. However, such stations are usually rather distant if you're using a good outdoor antenna. I have one that behaves like this, but it's about 85 miles away.

If you had this antenna setup last fall and winter, did you have good reception on 34 (33.1) then?

I removed the link and added the image above.
And yes I did tune it in the winter but it has not given me trouble all summer. My problem is a quality issue, I only notice problems when watching, Mercy, the office, Community and such but not when watching Sunday night football or Jay Leno. The image is interlaced but worse than you would expect or see normally. See attached image

Those are not problems with your RF signal reception, it's a receiver/display problem or a problem with the station.

Tvfool Attached

I am having trouble with Channel 34 (33.1) I have a 4228HD antenna about 5' above my roof, I just recently started having trouble with this channel. I have the antenna joined to another antenna via a channel 34 Jointenna. The signal reads about 80% and then will drop to 40% and back to 80%. I was wondering what would be the most likely cause for this issue. The signal should be very strong in my area but it is somewhat distant. I am in the suburbs and there are many trees. Also, would tilting my antenna up help?

You mention two antenas joined together. Are they both UHF antennas, and are they aimed in different directions?

I can also receive the signal from 8(7.1) which is also NBC but in the other direction. That signal does not display the same issues but it does come in an out more often since it is weaker, could I assume that all NBC broadcast are equal aside from their transmission, so assuming that, should eliminate the problem being with my receiver and more likely with the transmission. Note if it the problem were with my reception could it be that when the signal drops to 60% I am not receiving enough data to refresh the screen properly during panning sequences and hence the exagerated interlacing.

You mention two antenas joined together. Are they both UHF antennas, and are they aimed in different directions?

They are pointed about 135° out from one another but they are connected via a "Jointenna". The only channel that passes from the 4228HD is 34 all the rest come from the other antenna except channel 34.

I can't find a channel 34 jointenna manufactured by ChannelMaster. Could I get a part number from you to see what the isolation on channel 34 would be?

All UHF jointennas are custom configured for the channel requested. It allows one channel to pass from one side of the unit to the down feed and it allows all the rest of the channels to pass from the other side to the down feed. there is a knock out of channels 33 and 35 because of nature of design you loose the channel above and below the desired isolated channel. You can order them from Warren Electronics.

...Note if it the problem were with my reception could it be that when the signal drops to 60% I am not receiving enough data to refresh the screen properly during panning sequences and hence the exagerated interlacing.The "interlaced" problem in the image is not indicative of a poor signal.

A low or distorted signal would show up as freezing, pixelization and/or audio dropouts.